1.8.2 Fixation Req Flashcards
Factors to achieve adequate Fixation:
pH?
6-8
Factors to achieve adequate Fixation:
Osmolality?
Slightly hypertonic
In Board Exam, what is the prefered osmolality in Fixative (If there is no Slighlty hypertonic)
Isotonic
Factors to achieve adequate Fixation:
Vol?
20X vol of the specimen
Factors to achieve adequate Fixation:
Size of tissue to be processed?
3x2 cm
Factors to achieve adequate Fixation:
Thickness of tissue to be processed
3-5 mm
Factors to achieve adequate Fixation:
Thickness of tissue if LUNG EDEMA
1-2 cm
Factors to achieve adequate Fixation:
Fix temp for EM and Histochem?
0-4 C
Factors to achieve adequate Fixation:
Fix temp using autotechnicon
40C
Factors to achieve adequate Fixation:
Temp for Manual Fixation?
RT
Factors to achieve adequate Fixation:
Penetration rate of formalin
1mm/hr
Factors to achieve adequate Fixation:
Temp to ACCELERATE fixation?
37-56 C
Autotechnicon can be done up until only infiltration
T or F
T
Factors that can RETARD (prolong Fixation) time?
a. Size and thickness (Large tissue)
b. Cold temp
c. Presence of Blood
d. Presence of Mucous
e. Fatty tissues
Which among does not belong?
None
Blood and Mucous can prolong time fixation due to blockage of fixation
T or F
T
Remedy for Blood and Mucous in tissue (If you want to remove)
Wash with NSS
Remedy for Fatty tissue (If you want to remove)
Cut tissues thinly
Factors that can Accelerate fixation?
a. Size and thickness (Small size)
b. Agitation
c. Heat application
Which of the following does not belong?
None
What is the Routine Tissue Fixative?
10% NBF (Phosphate Buffer)
What are the Non-additive fixatives?
Alcohol and Acetones
Nuclear has a pH less than 4.6
T or F
T
Carnoy’s Bouin’s, newcomer’s Heidenhain Susa, Flemming’s With HAc
Nuclear fixative
Regaud’s / Moller’s
Orth’s
Formalin with post chroming Flemming’s without HAc
These are known as what type of Fixatives?
Cytoplasmic Fixatives
Cytoplasmic Fixatives has a pH more than 4.6
T or F
T
Aldehyde (Formaldehyde, Glutaraldehyde)
Which among use for electronmicrosopy?
Glutaraldehyde
In glutaraldehyde:
Small tissue fragments/ needle biopsies: ____
Larger tissue less than 4mm: ____
2.5%
4%
Formaldehyde:
10% Formol saline
10% Neutral Buffered formalin
Formol corrosive/formol sublimate
Alcoholic formalin/Gendres
These are all _______ formalin
Diluted
100mL of 37-40% formalin + 900ml distilled water
10% Formalin (NBF)
Added to prevent precipitation of formaldehyde to white paraformaldehyde
10% methanol
Mercuric Chloride + Formaldehyde
Formal Corrosive / Formal Sublimate
Formaldehyde:
Preserve CNS tissues lipids or phospholipids
10% Formol saline
10% Neutral Buffered formalin
Formol corrosive/formol sublimate
Alcoholic formalin/Gendres
10% Formol saline
Formaldehyde:
Preserve Tissues with iron pigments
10% Formol saline
10% Neutral Buffered formalin
Formol corrosive/formol sublimate
Alcoholic formalin/Gendres
10% Neutral Buffered formalin
Formaldehyde:
Micro incineration technique
10% Formol saline
10% Neutral Buffered formalin
Formol corrosive/formol sublimate
Alcoholic formalin/Gendres
Alcoholic formalin/Gendres
3 types of Metallic fixatives:
Chromate
Mercuric chloride
Lead
T or F
T
3 types of Metallic fixatives:
Use for Acid Mucopolysaccharide
Chromate
Mercuric chloride
Lead
Lead
3 types of Metallic fixatives:
Use for Carbohydrates, Potassium, etc
Chromate
Mercuric chloride
Lead
Chromate
CHROMATE Fixatives:
1-2 % chromic acid: ____________
3% Potassium dichromate: _______, mitochondria
Carbohydrates
Lipids
CHROMATE Fixatives:
____________: Mitochondria, RBC and colloid containing tissues
_____: Ricketssiae and other bacteria, tissue necrosis
Regaud’s / Moller’s
Orth’s
Most Common Metallic fixative
EXCELLENT for trichome staining and Tissiue Photography
Mercuric fixatives
Mercuric chloride Fixative:
Liver spleen, CT and nuclei
a. B5
b. Zenker’s
c. Helly’s fluid
b
Mercuric chloride Fixative:
Bone marrow
a. B5
b. Zenker’s
c. Helly’s fluid
a
Mercuric chloride Fixative:
Pituitary gland, BM, spleen, liver
a. B5
b. Zenker’s
c. Helly’s fluid
c
Mercuric chloride Fixative:
Tumor skin biopsies
Heidenhain’s Susa
Also known as Helly’s fluid
Zenker-Formol